Overview

Marsh Creek site 4 is located near Sunnybrook Lane. Sandy Springs Ga, less than half a mile west of Roswell Road (aka Hwy 9). Roswell Road is a high traffic area as well as a state highway. The particular area this site is located in is considered light residential while a medium residential area consisting of apartment buildings is located to the northeast. A commercial property is located just to the southeast of the site while more apartments are located to the south. Upstream, the creek crosses under Roswell Road before making its way downstream to this site.

Land Uses/Activities and Impervious Cover

A survey conducted adjacent to this site determined that no immediate impervious surfaces encroached this property. However there is a tennis court relatively close to the site at the apartments located to the south as well as a parking lot for the apartments northeast of the property. The concrete wall on the right bank (looking upstream) that serves as a retainer wall does not contribute to non-point source pollution, but may contribute to other issues such as channeling and erosion.

General Water Body and Watershed Characteristics

This site at Marsh Creek had a reach of 180 feet. The full bank width was found to be forty-three wide and stream bed width of fifteen feet. There were three pipes along the stretch. At the beginning of the reach along the left-side was a forty-eight inch corgated pipe with low flow. About fifteen feet further upstream on the right side of the bank was a fifteen inch concrete pipe near an eight inch metal pipe. In addition to the pipes was a large run-off ditch along the right side of the bank with extremely low flow. There were three runs, three ripples, and three pools; two bends also dissected the reach. Along the left side of the bank was a ten feet tall and 100 feet wide solid concrete retaining wall. There was severe erosion along the right side of the bank where the concrete wall extended on the left. The erosion continued up-stream along both banks for the remaining stretch of stream. Sedimentation was present consisting of cobblestones and sand in rippled areas: the sediment was mostly embedded.

Additional Comments

This site had a high turbidity level every time it was visited. There were no amphibians, reptiles, or aquatic mammals/birds sighted near the stream. However, small (1-3in) and medium sized fish (4-7in) were frequently observed in pooling areas. A few macro invertebrates were found on the site belonging to orders Odonata, (Dragonfly), and Diptera, (Crane Flies/ Midge Flies). Green alga growth along the water's edge was also regularly observed with minimal aquatic plants in and around the stream. Small non-point source pollution was occasionally found consisting of mixed debris.

MC4 hw erosion.JPG
Dredge spoil creating erosion that caused this headwall to disconnect from the pipe



MC4 drainage pipe.JPG
48" drainage pipe next to a retainer wall

All water quality samples were taken just downstream of this pipe to maximize possibility of detecting pollution.

MC4 Downstream.JPG
Downstream view. Group 4 recording data

Down stream erosion is not as severe as upstream.










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